Constraints on stellar evolution from pulsations

RADIATIVE OPACITIES AND STEllAR PULSATIONS

Stellar pulsations excited by a scattered mass

We compute the energy spectra of the gravitational signals emitted when a mass m0 is scattered by the gravitational field of a star of mass M >> m0. We show that, unlike black holes in similar processes, the quasi-normal modes of the star are excited, and that the amount of energy emitted in these modes depends on how close the exciting mass can get to the star. PACS numbers: 04.30.-w, 04.40.Dg...

Nonlinear Pulsations of Convective Stellar Models

We review the numerical modelling of the nonlinear pulsations of classical variable stars with hydrocodes that include the effects of turbulent convection. Despite their simplicity these turbulent convective recipes appear to remove many of the difficulties that radiative codes faced. In particular, the numerical modelling of double mode pulsations has become possible.

Effects of Uniform and Differential Rotation on Stellar Pulsations

We have investigated the effects of uniform rotation and a specific model for differential rotation on the pulsation frequencies of 10 M⊙ stellar models. Uniform rotation decreases the frequencies for all modes. Differential rotation does not appear to have a significant effect on the frequencies, except for the most extreme differentially rotating models. In all cases, the large and small sepa...

The evolution of the Milky Way from its earliest phases : constraints on stellar nucleosynthesis

We computed the evolution of the abundances of O, Mg, Si, Ca, K, Ti, Sc, Ni, Mn, Co, Fe and Zn in the Milky Way. We made use of the most widely adopted nucleosynthesis calculations and compared the model results with observational data with the aim of imposing constraints upon stellar yields. In order to fit at best the data in the solar neighborhood, when adopting the Woosley and Weaver (1995)...